Information: This liquid substrate for peroxidase consists of tetramethylbenzidine (TMB) plus dilute hydrogen peroxide in a single-reagent stabilized form. The reagent has been specifically formulated for measuring peroxidase on membranes and other surfaces and is not intended for use in microwell applications. This reagent is stable for long-term storage, and provides sensitivity equal to, or greater than, that of other commercially available chromogens.